Electric clock.



R. D. HIGKOK.

ELECTRIC GLOGK.

APPLICATION FILED MAR, 27, 1908.

90%128. Patented Nov. 1?. 1908.

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ROBERT D. HIGKOK, OF ATLANTA, GEORGIA.

Emerald cLocK.

Specification of Letters Patent.

Patented Nov. 17, 1903.

Application filed March 27, 1908. Serial No. 423,678.

To all whom it may concern:

Be it known that I, ROBERT D. HrcKoK, a citizen of the United States,residing at Atlanta, in the county of Fulton and State of Georgia, haveinvented certain new and useful Improvements in Electric Clocks, ofwhich the following is a specification.

This invention relates to electric clocks in which impulses are given tothe pendulum by means of electro magnets which are periodicallyenergized, and the object of the invention is to form an improvedmechanism for closing the circuit and actuating the electro magnets whenthe pendulum vibrations fall to a predetermined minimum. The advantageof this type of apparatus is that the current is only used when itbecomes necessary, to continue the vibrations of the pendulum; 1

The invention is illustrated in the accompanying drawings, in whichFigure 1 is an elevation showing the circuit closing devices in oneposition. Fig. 2 is a similar view with the said devices in differentposition. Fig. 3 is a detail in side or edge view of the parts. Fig. 4is a section on the line 44, looking down. Figs. 5 and 6 are enlargeddetails showing a pendant and a pin which is caught thereby at theminimum vibration.

Referring specifically to the drawings, 0 indicates the pendulum rodwith a slot N into which a pin M projects from the lower bar' of a frameP the upper ends of which are connected to the armature V which ispivoted at o to vibrate between the poles X and N of the electro magnetsm and to. One

side or arm of the frame P has secured there to, on its inner edge, aflat spring D, attached by a screw Q. An adjustable screw E passesthrough the frame and presses against the inner or rear side of thespring. At the lower end the spring carries a block with a forwardlyprojecting pin C; and the screw E may be adjusted to movethe spring, andconsequently the pin, to the right or left, to bring the clock in beat.

G indicates a circular bridge or hearing support in whichis mounted forvibration an arbor T which carries an arm F which stops against ashoulder f on the bridge, and which causes its position at rest to be asshown in Fig. 1. From the arm F is suspended, by a pivot a, aninvertedV-shaped pendant A. This is pivoted at the top, at

the angle, and the two arms balance each from the arm F, and isconveniently'fixed.

to the arm and the arbor by screws k. The

arbor byla strip of mica k thereunder andof the circuit terminates'in ascrew J pr plate S of the movement.

the connection at the pin M, and the pin C swings with the frame. Theparts are so ar: ranged that the pin will strike the V-shaped piece Hasthe parts vibrate. On the vibra tion from left to right the pin willstrike erly positioned to receive the contact of t e outer end of thespring H.- All of the arts described are suitably supported on the ackIn operation, the pendulum rod 0 and the frame P oscillate together, byreason of spring H is insulated from the arm and the.

and lift said piece and will pass under and beyond the same, and on thereturn beat,

from right to left will again strike the inolined side of said piece andswing the same down and pass thereover. The spring H is" normally out ofcontact with the screw J, and consequently no current is transmitted.When the pendulum reaches the predetermined point of minimum vibrationthe pin C lifting the same, and said piece will immediately drop,engaging the pin in the groove or V-shaped recess on the under sidethereof, The pendulum then starts to swing to'the' left carrying with itthe piece B angLthe pendant A until their paths diverge, and inconsequence of the shorter radius of the pendant A the effect is to liftsaid pendant, and the arm F, as shown in Fig. 2, thereby turnin thearbor T to an extent sufiicient to press t%e spring H a ainst thecontact point will not pass the piece B, but at the end of the beat willstop directly thereunder, after.

, whereby the circuit is closed and the imby insulating bushings aroundthe screws. The wire L forming one side of the circuit to the electromagnets is connected tofsaid. spring H, and the wire K on the other sidepulse is imparted to the armature by means 1 .minimum at which point theengagement between the pin and the pendant is effected in the mannerabove described and the circuit is thereupon closed. The pin 0, beingcar- .ried by the spring D, allows it to be adjusted to the right or'left, thus allowing the clock to be put exactly in beat. The use of thesprin 1) also prevents the breakage of the pin if at any time said pinshould catch upon said piece B when the pendulum is travelin to theright. It is evident that if the pin were rig-idly held and should catchas stated, either the pin or the pivot of the pendant A would receivethe full momentum of the pendulum and would therefore be broken.

A minimum amount of power is required to operate the device for thefollowing reasons: first, because the only parts of the device inmotion-when not making contactare the pendant A and the pin C, and saidpendant being made of aluminum or other light metal and delicatelybalanced, with jeweled pivots if desired, a minimum amount of power isrequired to operate it;

-second, because at those vibrations at which 7 contact is made thepower required to lift the arm F- and swing the spring H down to contactis in fact only that needed to overcome the friction of the pivots andthe inertia of the parts, for the arm F is lifted to its highestposition during the first half of the motion of the pendulum to theleft, and returns to its original position during the last half of themotion to the left, and

as it returns to its original position it necessarily gives its weightto the pendulum; or in other words,.the. power re uired to lift the armF during the first ha f of the motion to the left is returned to thependu- 111m during the last half of the motion to the left. Theengagement between the pin and the ooved piece, when the pendulumreaches t e minimum beat, is quite certain, because they are presentedto or toward each other in horizontal position and because of the wideplace of engagement thus pro- ,vided, slight variation in the plane ofoscillation is not apt to cause them to miss engagement and thus fail toclose the circuit.

I claim: 1. In an electric clock, the combination with the pendulum rod,of an armature frame which is connected thereto and swings therewith, anadjustable spring carried by the armature frame and having aprojection,-

and means actuated by said projection to minimum swing. of the pendulum.

2. Inan electric clock, the combination of close the clock circuit at apredetermined I a pivoted arm, a circuit closing contact spring carriedthereby, a pendant hanging from the arm, and means actuated by thependulum-of the clock on minimum swing thereof to engage and'lift thependant and turn the arm circuit. 3. In an electric clock thecombination with a swinging pendant having a horizontal piece projectintherefrom with a groove inand the spring to close the its under side, ofa frame vibrating with the v pendulum and having a horizontal pinarranged to strike said piece and swing-the pendant as the pendulumvibrats, and constructed to engage 111 said groove on 1111111 mumvibration, andimeans actuated by the in will strike the piece and dant,when the pin is so engaged, to close the clock circuit. Y

5. In an electric clock the combination of a pivoted arm arranged toswing vertically v and having a projecting contact spring, a pendantconsisting of an inverted V-shaped piece pivoted at' its-apex to thefree end of the arm, and having a horizontal grooved piece projectinglaterally from one branch thereof, a swinging frame oscillating with thependulum, and a pin projecting from the frame and arranged to strike andswing the pendant and to engage in the said groove on minimumoscillation of the frame.

In testimony whereof, I affix my signature, in presence of twowitnesses.

ROBERT D.-HICKOK. Witnesses:

.- E. F. CH'ILDRnss,

JAMES E. WARREN.

